+.BR "mhparam datalocking" .
+By default, fcntl locking is used, but this may be overridden by
+the
+.B datalocking
+profile entry.
+.PP
+A second, possibly different, locking method is used by
+.IR inc (1)
+when accessing the user's mail spool file or by
+.B nmh
+programs that open any mbox file. This locking method can be overridden
+when
+.B nmh
+is configured, or in the
+.B nmh
+mts configuration file, and can be accessed as a string using
+.BR "mhparam spoollocking" .